Locust.io - an open source load testing tool. Define user behaviour with Python code, and swarm your system with millions of simultaneous users.
PsySH - a runtime developer console, interactive debugger and REPL for PHP. Looks like the coolest dev tool after xDebug. But could not run debug correctly on basic Vagrant+Apache due to missing $HOME env param.
Locust.io - an open source load testing tool. Define user behaviour with Python code, and swarm your system with millions of simultaneous users.
Workerman - a library for event-driven programming in PHP. Alternative to ReactPHP.
Trailblazer - a new Concept or a Domain Driven application structure for Rails. Tries to get rid of fat models, monolithic controllers, global helpers, etc.
ramjet - morph DOM elements from one state to another with smooth transitions